1. Field of the Invention
The present invention relates to an improved panel for a sectional door.
The invention also relates to an improved sectional door incorporating the improved panels.
2. Relevant Art
Sectional doors are well known. They comprise a plurality of identical, elongated panels which panels are hinged together along their long sides. The doors can be moved between two positions about a curve and are commonly used to close openings in garages. To open a garage, the door is raised from a closed, vertical position about curved tracks to an open, horizontal position. Examples of such doors are shown in U.S. Pat. Nos. 2,880,796; 3,941,180; 3,967,671 and 4,119,133.
The panels in the sectional door are often composed of a central core of insulating material covered with a metallic skin. Such panels provide a door which is strong, yet light in weight, and which has some insulating properties. The central insulating core often comprises a plastic foam material expanded in place within the metallic covering skin. U.S. Pat. Nos. 2,880,796 and 4,119,133 disclose panels of the above type by way of example.
Sealing means are usually provided between the panels to seal the door tightly in its operative position. The sealing means often comprise separate sealing strips fixed to the long sides of the panels. U.S. Pat. No. 4,119,133 shows such sealing strips by way of example.
The doors made from panels consisting of an insulating core covered with a metallic skin are not as efficient in insulating as they could be. Indeed, heat from within the closed garage is conducted to the outside by the metallic skin covering the insulating core. This heat loss can be considerable.
To obviate this problem, it has already been proposed to insert insulating segments between a pair of metallic skins covering each side of the core. U.S. Pat. Nos. 3,750,333; 3,837,134; 3,599,703 are illustrative in this regard. However, such a solution substantially increases the cost of construction of the panels as it requires additional parts to stock and additional time for the assembling operation.